The Layers of the Earth (Earth & Space)

Lesson notes

Overview

From a thin crust to a vast mantle and a metallic core. This topic is rated beginner and is number 9 of 98 in Earth & Space. Core ideas and first intuitions. No prior knowledge needed.

What you are seeing

The panel above shows a bar chart that compares values on one scale, so differences in size are easy to see. The animation is drawn live from the model, so everything you see responds to the sliders. Press Space to pause, use Restart to replay from the start, and change the speed to slow down quick events.

In depth

The Earth has a thin rocky crust, 5 to 70 km thick, a thick mantle of hot, slowly flowing rock extending to 2,900 km, a liquid iron–nickel outer core and a solid inner core with a radius of about 1,220 km. Their existence was deduced from how seismic waves travel: S-waves do not pass through the liquid outer core, and waves refract at boundaries. The temperature rises to about 5,000 °C at the centre, and the motion of the outer core generates the magnetic field.

Reading the relationship

The expression "thickness" is a compact summary of the idea. It uses the symbols t, h, i, c, k, n; name what each one stands for before you start. Then use the sliders to see how changing one quantity changes the others.

A guided exploration

1. Run the animation once with the default settings and describe in words what happens. 2. Change one slider at a time and note which quantity responds most. 3. Push each slider to its extreme and decide whether the result still makes sense.

Try this

Start by only moving one slider at a time. Say aloud what you expect, then check.

Common pitfalls

Earth and space systems work on very different scales of time and distance. Check which scale a number refers to before comparing it with another.

How it connects

It builds on “Tsunami Speed”, the topic before it in Earth & Space. Once you are comfortable, continue with “Mohs Hardness Scale”.

Why it matters

Earth and space science helps us understand our planet, its climate and the wider universe.

Where you might use it

Revising “The Layers of the Earth” before a class, exam or certification
Forecasting weather and understanding climate records and their uncertainty
Planning for earthquakes, floods and other natural hazards in cities
Interpreting satellite images, space missions and the age of rocks and stars

Frequently asked questions

What is The Layers of the Earth?

From a thin crust to a vast mantle and a metallic core. It is a beginner topic in Earth & Space.

How do I use the The Layers of the Earth simulation?

The panel at the top shows a bar chart that compares values on one scale, so differences in size are easy to see. Move the sliders one at a time, then press Space to pause the animation and look closer.

What does the formula mean?

The expression thickness packs the idea into symbols. Name each symbol first, then change one quantity with the sliders and see which others respond.

Who is this topic for?

Core ideas and first intuitions. No prior knowledge needed. If the quiz feels hard, reread the lesson notes and try the previous topic first.

What should I learn before this?

Start with “Tsunami Speed”, the previous topic in Earth & Space. Each topic in a subject builds on the ones before it.

How do I track my progress?

Press “Mark as learned” on this page. Progress is stored only in this browser and is never sent anywhere. The Browse page can show topics you have learned or still need to learn.